Polycarbonate chemistry

- May 31, 2019-

  Polycarbonate (PC) is a carbonic acid polyester. Carbonic acid itself is not stable, but its derivatives (such as phosgene, urea, carbonate, carbonate) have certain stability. The polycarbonate can be classified into two types, aliphatic and aromatic, depending on the structure of the alcohol. Aliphatic polycarbonate. Such as polyethylene carbonate, polytrimethylene carbonate and its copolymer, low melting point and glass transition temperature, poor strength, can not be used as structural materials; but with its biocompatibility and biodegradable properties, It has been applied in drug release delivery vehicles, surgical sutures, and bone support materials. Polycarbonate is resistant to weak acids, weak bases and neutral oils. Polycarbonate is not resistant to UV light and is not resistant to strong alkali.

  PC is a linear carbonic acid polyester in which carbonic acid groups are alternately arranged with other groups. These groups may be aromatic, aliphatic or both. Bisphenol A type PC is the most important industrial product. PC is an almost colorless glassy amorphous polymer with good optical properties. PC high molecular weight resin has high toughness, cantilever beam notched impact strength is 600~900J/m, unfilled grade has a heat distortion temperature of about 130 °C, and glass fiber reinforced can increase this value by 10 °C. The flexural modulus of PC can reach more than 2400 MPa, and the resin can be processed into a large rigid product. Below 100 ° C, the creep rate under load is very low. PC is poor in hydrolysis resistance and cannot be used to repeatedly process articles subjected to high pressure steam.

  The main performance defect of PC is that the hydrolysis resistance is not high enough, it is sensitive to the notch, resistant to organic chemicals, and has poor scratch resistance. It will yellow when exposed to ultraviolet light for a long time. Like other resins, PCs are susceptible to attack by certain organic solvents. PC materials are flame retardant and wear resistant. Antioxidant.